The present invention relates to an optical integrated circuit device, having a protrusion, a fabrication method of the same and a module of an optical communication transmission and receiving apparatus using the same, and in particular to an optical integrated circuit device having a protrusion, a fabrication method of same and a module of an optical communication transmission and receiving apparatus using the same which are capable of easily aligning the position of an optical integrated circuit device and optical fiber when assembling an optical communication transmission and receiving apparatus module, obtaining a short position aligning time and preventing a crack phenomenon at a corner portion of an optical integrated circuit device.
Generally, in order to align a light source (an optical integrated circuit device like a laser diode chip and a photo diode chip) of an optical communication transmission and receiving apparatus module capable of converting an electrical signal into an optical signal or an optical signal into an electrical signal and an optical fiber, an active alignment method and a passive alignment method are used.
The active alignment method requires a long time for aligning a laser diode and an optical fiber for thereby decreasing a mass production. In addition, the active alignment method needs many parts, so that it is impossible to implement a low cost product.
Therefore, the passive alignment method in which a current is not applied to a laser diode, and a laser diode and an optical fiber are directly coupled is increasingly used.
FIG. 1A is a disassembled perspective view illustrating an optical communication transmission and receiving apparatus module for explaining a conventional active alignment method with respect to an optical integrated circuit device and an optical fiber.
As shown therein, the optical communication transmission and receiving apparatus module includes a mounting apparatus 100 for mounting an optical integrated circuit device, an optical fiber, etc. an optical fiber 110 installed in a V-shaped longitudinal groove 101 formed on an upper portion of the mounting apparatus 100, and an optical integrated circuit device (here, a laser diode) installed at an end portion of the optical fiber 110. At this time, a laser diode chip 120 is aligned and attached on an upper portion of the mounting apparatus 100 in such a manner that an active layer 121 which is a light emission layer of the laser diode chip 120 is positioned at the center of the optical fiber.
In order to implement an accurate alignment, a rotation adjusting mark 103, an optical axis adjusting mark 105, etc. are formed on an upper surface of the mounting apparatus 100. A position adjusting mark 123 is formed on the laser diode 120. FIG. 1A is a view of a method for checking whether the positions of the above marks are accurately aligned using an infrared ray camera. The optical fiber 110 and the active layer 121 of the laser diode chip 120 are matched in the above method.
FIG. 1B is a disassembled perspective view of a conventional communication transmission and receiving apparatus module for explaining another example of a position alignment method with respect to an optical integrated circuit device and an optical fiber.
As shown therein, a V-shaped groove 151 is formed on an upper surface of the mounting apparatus 150. An optical fiber 160 is installed on an upper portion of the V-shaped groove 151. A concave portion 152 is formed at an end of the V-shaped groove 151 for mounting the optical integrated circuit device 170 therein. A convex portion 171 corresponding to the concave portion 152 is formed on the surface of the optical integrated circuit device 170. The convex portion 171 of the optical integrated circuit device 170 is inserted into the concave portion 152 of the mounting apparatus 150, so that the optical fiber 160 and the active layer 172 of the optical integrate circuit device 170 are matched.
However, the above-described conventional position alignment method has the following disadvantages.
The method of FIG. 1A has an advantage in that the number of parts is decreased for aligning the optical integrated circuit device and the optical fiber. However, since an expensive flip chip bonder which requires an accurate resolution is used, the installation cost of the equipment is high. In addition, the above method is not better than an active alignment method in a view of the process time. The method of FIG. 1B will be explained with reference to FIGS. 2A and 2B. FIGS. 2A and 2B are vertical cross-sectional views taken along line IIaxe2x80x94IIa after mounting the optical integrated circuit device 170 of FIG. 1B on the mounting apparatus 150.
FIG. 2A is a view illustrating a convex portion 171 formed on an upper surface of the conventional optical integrated circuit device 170 in which a lateral surface 172a has a vertical profile. FIG. 2B is a view illustrating a convex portion of the conventional optical integrated circuit device 170 in which a lateral surface 172b has a reverse taper.
As shown in FIGS. 2A and 2B, the size L1 of the concave portion of the mounting apparatus 150 is larger than the size L2 of the convex portion 171 of the optical integrated circuit device 170. Therefore, as shown in FIGS. 2A and 2B, the convex portion 171 is inserted into the convex portion 152 of the mounting apparatus 150. The optical integrated circuit device 150 is horizontally moved so that the lateral surfaces 152a and 152b of the concave portion 152 and the lateral surfaces 171a and 171b of the convex portion 171 closely contact each other.
At this time, in the case of the convex portion 171 having a nearly perpendicular lateral wall profile, when inserting the convex portion 171 into the concave portion 152, an end portion A of the convex 171 collides with an upper portion of the mounting apparatus 150, so that the end portion A of the same may be cracked.
In the case that the convex portion 171 having a reverse taper lateral wall profile, an end portion B of the convex portion 171 may collide with a lateral wall of the concave portion 150 of the mounting apparatus, so that the end portion B of the same is cracked. Therefore, a certain defect may occur in the optical integrated circuit device due to the cracks. In addition, a matching property of an alignment between the optical fiber and the optical integrated circuit device may be decreased due to the reverse taper lateral wall profile.
Accordingly, it is an object of the present invention to provide an optical integrated circuit device and a fabrication method of the same which are capable of easily aligning the position of an optical integrated circuit device and optical fiber when assembling an optical communication transmission and receiving apparatus module, obtaining a short position aligning time and preventing a crack phenomenon at a corner portion of an optical integrated circuit device.
To achieve the above objects, there is provided an optical integrated circuit device comprising a semiconductor substrate, a convex portion formed on an upper surface of the semiconductor substrate and having a taper shape lateral surface, a protection film formed on a lateral wall surface of the convex portion, a first electrode formed on an upper surface of the convex portion, and a second electrode formed on an upper surface of the semiconductor substrate, wherein the convex portion is formed of a first current disconnection layer, a second disconnection layer and a clad layer.
A gradient of the lateral wall surface of the convex portion is 10xcx9c70xc2x0 in a direction perpendicular from the surface of the semiconductor substrate.
The protection film is formed of a silicon film or a silicon nitride film.
To achieve the above object, there is provided an optical integrated circuit device fabrication method comprising a step for selectively growing an active layer on an upper surface of a semiconductor substrate using a MOCVD method, a step for selectively growing a first current disconnection layer on an upper surface of the semiconductor substrate at both sides of the active layer using the MOCVD method, a step for selectively growing a second current disconnection layer on an upper surface of the first current disconnection layer, a step for growing a clad layer on an upper surface of the second current disconnection layer and an upper portion of the active layer, a step for forming an etching mask on an upper surface of the clad layer on the active layer, a step for sequentially etching the clad layer, the second current disconnection later and the first current disconnection layer which are not covered by the etching mask and exposing an upper surface of the semiconductor substrate, a step for removing the etching mask, a step for forming a protection film on the lateral walls of the clad layer, the second current disconnection layer and the first current disconnection layer, and a step for forming a first electrode on an upper surface of the protection film and a second electrode on an upper surface of the semiconductor substrate.
The etching step is performed by a chemical etching method.
The etching solution used for the chemical etching method is HCL:P3OH or HCL:CH3COOH.
The protection layer is formed of a silicon oxide film or a silicon nitride film.
To achieve the object, there is provided an optical communication transmission and receiving apparatus module comprising an optical integrated circuit device including a semiconductor substrate, a convex portion formed on an upper surface of the semiconductor substrate and having a taper shaped lateral surface, a protection film formed on a lateral wall surface of the convex portion, a first electrode formed on an upper surface of the convex portion, and a second electrode formed on an upper surface of the semiconductor substrate, wherein the convex portion is formed of a first current disconnection layer, a second current disconnection layer and a clad layer, a mounting apparatus having a concave portion having a reverse tape shaped lateral wall profile at an upper center portion of the same, a third electrode having a portion embedded in the mounting apparatus and another portion being extended to a lower surface of the concave portion, and a fourth electrode formed on an edge upper surface of the mounting apparatus, wherein the third electrode formed on a lower surface of the concave portion of the mounting apparatus and the first electrode of the optical integrated circuit device contact each other, and the second electrode of the optical integrated circuit device and the fourth electrode contact each other, and the protection film contacts with a lateral wall of the concave portion, so that the optical fiber and the optical integrated circuit device are manually aligned.